Determining a location of a wireless endpoint device in a wireless network

ABSTRACT

A method, computer readable medium and apparatus for determining a location of a user endpoint device in a wireless network are disclosed. For example, the method receives from each of a plurality of base stations a plurality of signals and a plurality of times of arrival, wherein each of the plurality of times of arrival is associated with a particular signal of the plurality of signals, and determines the location of the wireless endpoint device from the plurality of signals and the plurality of times of arrival.

This application is a continuation of U.S. patent application Ser. No.13/715,833, filed Dec. 14, 2012, now U.S. Pat. No. 9,026,137, which isherein incorporated by reference in its entirety.

The present disclosure relates generally to communication networks and,more particularly, to a method, computer readable medium and apparatusfor determining a location of a wireless endpoint device in a wirelessnetwork, e.g., in a cellular network such as an LTE (long termevolution) wireless network and the like.

BACKGROUND

More and more customers are using wireless endpoint devices to access orutilize various services. For example, a customer may use a cellular(cell) phone for accessing communications services, making purchases,conducting banking transactions, accessing various multimedia services,etc.

However, some services require an accurate knowledge of a location ofthe wireless endpoint device. However, the location of the wirelessendpoint device may not be available or may be inaccurate. For example,when a cell phone is indoors or in a city with high-rise buildings,Global Positioning System (GPS) information for the cell phone may notbe readily available or may be inaccurate. In addition, in someinstances, a wireless service provider may be constrained or entirelyprohibited from using the GPS information of the cell phone forproviding a service.

SUMMARY OF THE DISCLOSURE

In one embodiment, the present disclosure teaches a method, computerreadable medium and apparatus for determining a location of a userendpoint device in a wireless network. For example, the method receivesfrom each of a plurality of base stations a plurality of signals and aplurality of times of arrival, wherein each of the plurality of times ofarrival is associated with a particular signal of the plurality ofsignals, and determines the location of the wireless endpoint devicefrom the plurality of signals and the plurality of times of arrival.

BRIEF DESCRIPTION OF THE DRAWINGS

The teaching of the present disclosure can be readily understood byconsidering the following detailed description in conjunction with theaccompanying drawings, in which:

FIG. 1 is a block diagram depicting an illustrative network related tothe current disclosure;

FIG. 2 illustrates an exemplary network in accordance with oneembodiment of the current disclosure for determining a location of awireless endpoint device;

FIG. 3 illustrates a flowchart of a method for determining a location ofa wireless endpoint device;

FIG. 4 illustrates a flowchart of a method for determining a location ofa user endpoint device from the plurality of signals and the pluralityof times of arrival; and

FIG. 5 depicts a high-level block diagram of a general-purpose computersuitable for use in performing the functions described herein.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures.

DETAILED DESCRIPTION

The present disclosure broadly teaches a method, computer readablemedium and apparatus for determining a location of a wireless endpointdevice, e.g., in a wireless network such as an LTE wireless network andthe like. Although the teachings of the present disclosure are discussedbelow in the context of an LTE wireless network, the teaching is not solimited. Namely, the teachings of the present disclosure can be appliedfor other types of wireless networks, wherein locating a user endpointdevice is beneficial for providing services to the customers of awireless service provider.

Broadly defined, 3GPP is a global effort to define a wirelesscommunication system specification. 2G is a second generation cellularnetwork technology, 3G is a third generation cellular networktechnology, and 4G is a fourth generation cellular network technology. AGlobal System for Mobile (GSM) communications is an example of a 2Gcellular technology and a Universal Mobile Telecommunications System(UMTS) is an example of a 3G cellular network technology. In accordancewith the 3GPP global effort, a General Packet Radio Service (GPRS)refers to a communications service used to transfer data via a cellularnetwork. GPRS is available to users of a 2G cellular system GSM. TheGPRS provides an enhancement to the GSM system so that data packets aresupported. In addition, in 3GPP release 8, an LTE standard is providedas a set of enhancements to the UMTS. The enhancement focuses onadopting 4th Generation (4G) mobile communications technology to includean all Internet Protocol (IP) end-to-end networking architecture. An LTEis an example of a 4G cellular network technology.

A base station for a 2G network is also referred to as a basetransceiver station (BTS). A base station in a 3G network is alsoreferred to as a Node B. For the 4G network, a radio base transceiverstation (RBS), as per the 3GPP standards, is referred to as an eNodeB(or simply as a base station). An eNodeB provides an LTE-air interfaceand performs radio resource management for wireless access.

FIG. 1 illustrates an exemplary network 100 related to the presentdisclosure. In one illustrative embodiment, the network 100 comprises anLTE network 101, an IP network 113, other access networks 114, an IPMultimedia Subsystem (IMS) core network 115, and an LTE user endpointdevice 116. The user endpoint device 116 can be a smart phone, acellular phone, a computer or laptop, a computing tablet, or anyendpoint communication devices equipped with wireless capabilities.

In one embodiment, the LTE network 101 comprises access network 103 anda core network 105. In one example, the access network 103 comprises anevolved Universal Terrestrial Radio Access Network (eUTRAN). In oneexample, the core network 105 comprises an Evolved Packet Core (EPC)network. The eUTRANs are the air interfaces of the 3GPP's LTEspecifications for mobile networks. Namely, the eUTRAN comprises a radioaccess network standard that replaces previous generations of airinterface standards. All eNodeBs in the eUTRAN 103 are in communicationwith the EPC network 105. In operation, LTE user equipment or userendpoints (UE) 116 may access wireless services via the eNodeB 111located in the eUTRAN 103. It should be noted that any number of eNodeBscan be deployed in an eUTRAN. In one illustrative example, the eUTRAN103 may comprise one or more eNodeBs.

An EPC network provides various functions that support wireless servicesin the LTE environment. In one embodiment, an EPC network is an InternetProtocol (IP) packet core network that supports both real-time andnon-real-time service delivery across a LTE network, e.g., as specifiedby the 3GPP standards. For example, in EPC network 105, network devicesMobility Management Entity (MME) 107 and Serving Gateway (SGW) 108support various functions as part of the LTE network 100. MME 107 is thecontrol node for the LTE access-network. In one embodiment, the MME 107is responsible for UE (User Equipment) tracking and paging (e.g., suchas retransmissions), bearer activation and deactivation process,selection of the SGW, and authentication of a user. In one embodiment,SGW 108 routes and forwards user data packets, while also acting as themobility anchor for the user plane during inter-eNodeB handovers and asthe anchor for mobility between LTE and other wireless technologies,such as 2G and 3G wireless networks.

In addition, EPC (common backbone) network 105 may comprise a HomeSubscriber Server (HSS) 109 that contains subscription-relatedinformation (e.g., subscriber profiles), performs authentication andauthorization of a wireless service user, and provides information aboutthe subscriber's location. The EPC network 105 may also comprise aPublic Data Network (PDN) gateway (GW) 110 which serves as a gatewaythat provides access between the EPC network 105 and various datanetworks, e.g., other IP networks 113, an IMS core network 115, otheraccess networks 114 and the like. In one embodiment, the EPC network 105may also comprise a Policy Charging and Rule Function (PCRF) thatsupports accesses to subscriber databases and specialized functions of acharging system. The Policy Charging and Rule Function (PCRF) can beimplemented as a standalone module or implemented as a part of one ofthe other network modules of the EPC network 105.

It should be noted that the EPC network 105 as shown in FIG. 1 is onlyillustrative and is not limited to the network elements as describedabove, i.e., there could be additional network elements that aredeployed but not discussed.

It should be noted that although various networks are shown as separatenetworks in FIG. 1, it is possible that functions or operationsperformed by these networks can be combined into fewer networks orexpanded into a greater number of networks depending on the deploymentrequirements.

It should also be noted that the above illustrated network 100 is onlyillustrative and the number of network components or elements are notspecifically limited as shown. Any number of network components orelements can be deployed.

As the use of wireless technology grows, more and more customers areusing wireless endpoint devices to access or utilize various services.For example, a customer may use a smart phone for accessingcommunications services, perform financial transactions, etc. However,providing a service to the customer may require an accurate knowledge ofthe location of the customer's wireless endpoint device through whichthe customer is accessing the service. However, obtaining the exactlocation of the wireless endpoint device may not be readily possible.For example, when a cell phone is indoors or in a city with high-risebuildings, GPS information for the phone may not be readily available.In addition, in some instances the wireless service provider may belegally prohibited from using the GPS information of the cell phone forproviding a particular service.

A wireless service provider may wish to provide a service via an LTE(long term evolution) network. Unlike universal mobile telecommunicationsystems (UMTSs) and wideband code division multiple access (WCDMA)systems that have a fixed bandwidth of 5 MHz, LTE (long term evolution)provides a plurality of bandwidth options. For example, an LTE networkmay have a plurality of bandwidth options that comprise at least one of:1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz and 20 MHz. Due to theavailability of several bandwidth options, LTE networks have gainedpopularity.

However, LTE networks use an Orthogonal Frequency-Division Multiplexing(OFDM) scheme. In OFDM, a plurality of orthogonal sub-carrier signals isused to carry data on a plurality of parallel channels. The plurality ofsub-carrier signals are closely spaced and are chosen such that thesub-carriers are orthogonal to each other. The usage of orthogonalsub-carrier signals reduces or eliminates cross-talk between thechannels. The OFDM scheme enables a transmitter to transmit data as aplurality of low-rate parallel streams, instead of as one high-rate datastream. Consequently, data transported using OFDM is less affected bymultipath propagation as compared to data transported using a singlehigh-rate data streaming scheme. In OFDM, signals received from multipletransmitters may be constructively combined.

In one example, when a user endpoint device approaches a particularphysical location, a receiver at an adjacent eNodeB (a base station ofan LTE network) may receive a plurality of signals from the userendpoint device. For example, the receiver may receive a signal via adirect path between the user endpoint device and the eNodeB and anynumber of signals via indirect paths. The direct path is the shortestpath between the user endpoint device and the eNodeB. The direct path isthe path most closely related to the geometrical positioning of thetransmitters and receivers. The signals received via indirect paths maybe due to reflections that occur on surfaces of various structures suchas large natural terrains or man-made structures. The signals receivedvia the indirect paths are received as several multipath components.Thus, the receiver antenna of an eNodeB may receive multiple copies ofthe same signal at the same frequency transmitted by a wireless endpointdevice. The multiple copies that are received may be constructivelycombined. Similarly, the wireless endpoint device may receive a signalvia a direct path between the wireless endpoint device and the eNodeB,and any number of signals via indirect paths.

Since the OFDM signals are less affected by the particular path that theOFDM signal traverses, the receiver may be unable to distinguish amongvarious copies of a same signal received via different paths. As such,the receiver may not be able to ascertain an accurate time of arrivalfor a user endpoint device at a particular location. In one embodiment,the present disclosure provides a method for determining the location ofthe wireless user endpoint device solely from information collected frombase stations, e.g., from eNodeBs.

In one embodiment, the present disclosure provides an overlay LocationChannel (LOCH). The LOCH channel has low power and is spread uniformlyacross the entire bandwidth. The signal carried on the LOCH comprises aknown periodic sequence with a constant envelope and perfectautocorrelation properties. In one embodiment, the signal carried on theLOCH channel comprises a signal to which a Zadoff-Chu sequence isapplied. When the Zadoff-Chu sequence is applied to the signals, theresulting signal has a property wherein cyclically shifted versions ofthe signal are orthogonal to each other.

The LOCH channel is overlaid onto an LTE signal. For example, an LTEsignal is first encoded and modulated. Then, a LOCH channel, carrying asignal with a known periodic sequence with a constant envelope andperfect autocorrelation properties, is overlaid onto the LTE signal. Thecombined signal is then transmitted towards a receiver.

As described above, the signal carried on the LOCH comprises a knownperiodic sequence with low power. Thus, the receiver is able to extractthe signal carried on the LOCH prior to performing demodulation and datadecoding, without negatively affecting the performance of the receiver.

As noted above, the receiver may receive a plurality of signals via aplurality of paths. For instance, the receiver may receive one signalvia a direct path and any number of signals via indirect paths. Thereceiver then records a time of arrival for each of the plurality ofsignals that are received.

The receiver then extracts the overlaid LOCH from each of the pluralityof signals received. Once the LOCH is extracted, the remaining signal(LTE signal) may be processed using a normal procedure. For example, thedemodulation and decoding of the LTE signal may proceed using the normalprocedure. The content of the LOCH that is extracted is then provided toa Mobility Management Entity (MME). The MME gathers signals carried onLOCHs and their respective times of arrival. The MME then processes thecontent of each LOCH to determine the location of the transmitter thattransmitted the content towards the receiver. For the example above, thesignal carried on the LOCH may be processed by an MME to determine alocation of the user endpoint device that transmitted the signal towardsthe eNodeB.

The MME then identifies a string of multipath components of the signalcarried on the LOCH. For example, using the perfect auto-correlationproperties of the signal carried on the LOCH, the MME is able toidentify the string of multipath components in the signal carried on theLOCH.

The MME then determines an earliest time of arrival of a signal from atransmitter in accordance with the times of arrival that are collectedfrom receivers. The earliest time of arrival is a time at which anearliest arrival instance of a component of the string of multipathcomponents of the signal carried on the LOCH is received by an eNodeB.

The method then determines a location of a transmitter in accordancewith the earliest time of arrival that is determined. If the transmitteris a transmitter of the user's wireless endpoint device, the location ofthe transmitter is then the location of the user's wireless endpointdevice. The service provider may then provide a service using thelocation of the user's wireless endpoint device that is determined bythe MME, solely based on information collected from base stations, e.g.,from eNodeBs. For example, if the wireless endpoint device is at aparticular location and the location is needed to provide a service(e.g., a navigation service), the service provider is able to use thelocation that is determined for providing such service.

FIG. 2 illustrates an exemplary network 200 in accordance with oneembodiment of the current disclosure for determining a location of auser's wireless endpoint device. The service provider may implement themethod of the present disclosure for determining a location of a user'swireless endpoint device via a Mobility Management Entity (MME). The MMEcollects information from base stations, e.g., eNodeBs. A networkservice provider may provide to a customer a wireless endpoint devicewith a capability to overlay a location channel onto a signal of a longterm evolution (LTE) network, prior to transmitting a signal towards areceiver of a base station. The location channel carries a signal with aknown periodic sequence with a constant envelope and perfectautocorrelation properties. The service provider may then enablereceivers of base stations to provide to an MME: the content of eachLOCH that is extracted and their respective times of arrival. The MMEthen receives and processes the content of each LOCH times of arrivalsto determine the location of the transmitter that transmitted thecontent towards the receiver. For example, a signal carried on the LOCHmay be processed by an MME to determine a location of a user endpointdevice that transmitted the signal towards an eNodeB.

The network 200 comprises the LTE network 101, the IP network 113, otheraccess networks 114, the IP Multimedia Subsystem (IMS) core network 115,and an LTE user endpoint device 116. The LTE network 101 comprises anaccess network 103 and a core network 105. In one example, the accessnetwork 103 comprises an eUTRAN. The core network 105 comprises anEvolved Packet Core (EPC) network. The LTE user endpoint device 116 mayaccess wireless services via an eNodeB 211, an eNodeB 221 or an eNodeB231. All eNodeBs in the eUTRAN 103 are in communication with the EPCnetwork 105. The EPC network 105 provides various functions that supportwireless services in the LTE environment. The EPC network 105 comprisesan MME 207. The MME 207 is the control node for the LTE access-network101.

The service provider may implement the method of the present disclosurefor determining a location of a user endpoint device via the MME 207. Anetwork service provider may provide to a customer a wireless userendpoint device (UE) 116. The UE 116 has a capability to overlay alocation channel onto a signal of a long term evolution (LTE) network,prior to transmitting a signal towards a receiver of a base station. Thelocation channel carries a signal with a known periodic sequence with aconstant envelope and perfect autocorrelation properties.

The service provider may then enable receivers of eNodeBs 211, 221 and231 to provide to the MME 207: the content of each LOCH that isextracted and their respective times of arrival. The MME 207 collectsinformation from base stations, e.g., eNodeBs 211, 221 and 231. Forexample, a signal carried on the LOCH may be sent from eNodeB 211 to theMME 207.

The MME 207 then receives and processes the content of each LOCH andcorresponding times of arrivals to determine the location of thetransmitter that transmitted the signal towards the particular eNodeB.For the example above, the signal received (from the UE) by the eNodeBvia each LOCH is forwarded by the eNodeB towards the MME 207. Theforwarding is performed such that the signal may be processed todetermine the location of the UE. In one embodiment, the processing isperformed by first identifying a string of multipath components of thesignal transmitted on the LOCH from the UE to the eNodeB. The MME thendetermines an earliest time of arrival of a signal from a transmitter inaccordance with the times of arrival that are collected from the eNodeB.The earliest time of arrival is a time at which an earliest arrivalinstance of a component of the string of multipath components of thesignal carried on the LOCH is received by the eNodeB. The MME thendetermines a location of the UE that transmitted the signal to theeNodeB in accordance with the earliest time of arrival that isdetermined.

FIG. 3 illustrates a flowchart of a method 300 for determining alocation of a wireless endpoint device. In one embodiment, method 300may be implemented in a network element of a wireless network. Forexample, the network element of the wireless network may be a MobilityManagement Entity (MME) as illustrated in FIG. 2. Method 300 starts instep 305 and proceeds to step 310.

In step 310, method 300 receives from each of a plurality of basestations a plurality of signals and a plurality of times of arrival,wherein each of the plurality of times of arrival is associated with aparticular signal of the plurality of signals. For example, an MME mayreceive a plurality of signals from each of the base stations. Forexample, a signal may be transmitted on a location channel from a userendpoint device to any number of base stations. A particular basestation of the plurality of base stations may receive a plurality ofsignals from the user endpoint device via a plurality of paths. Each ofthe plurality of signals that is received via a particular path of theplurality of paths may then be extracted by the particular base stationand forwarded to the MME for analysis.

In step 320, method 300 determines a location of a user endpoint devicefrom the plurality of signals and the plurality of times of arrivalreceived from the plurality of base stations. For example, the methoddetermines an earliest time of arrival in accordance with the times ofarrival that are collected. The earliest time of arrival is a time atwhich an earliest arrival instance of a component of the string ofmultipath components of the signal carried on the LOCH is received by abase station of the plurality of base stations, e.g. a particular eNodeBof a plurality of eNodeBs that may have forwarded a signal to an MME.The method then determines a location of a wireless endpoint device inaccordance with the earliest time of arrival that is determined. Themethod then either proceeds to step 310 to receive more signals or tostep 395 to end the process.

It should be noted that each base station may receive a plurality ofsignals via a plurality of paths. Each particular base station records atime of arrival for each of the plurality of signals that is received.The particular base station then extracts the overlaid location channelfrom each of the plurality of signals that is received. Once thelocation channel is extracted, the remaining signals (received via theplurality of paths) are processed using a normal procedure. For example,the demodulation and decoding of the LTE signal, described above, mayproceed using the normal procedure. The content of the location channelthat is extracted from each signal is then provided to the MME. The MMEmay then perform method 300, as described above.

FIG. 4 illustrates a flowchart of step 320 of FIG. 3 in greater detailas method 400. Specifically, in step 410, the method 400 identifies astring of multipath components from the plurality of signals. In step420, the method 400 determines which component of the string ofmultipath components that are identified is associated with an earliestarrival time of the plurality of times. Finally, in step 430, the method400 determines the location of the user endpoint device in accordancewith the component of the string of multipath components that isassociated with the earliest arrival time. The method then ends in step495.

It should be noted that although not specifically specified, one or moresteps or operations of methods 300 and 400 may include a storing,displaying and/or outputting step as required for a particularapplication. In other words, any data, records, fields, and/orintermediate results discussed in the method can be stored, displayedand/or outputted to another device as required for a particularapplication. Furthermore, steps, blocks, or operations in FIGS. 3 and 4that recite a determining operation or involve a decision do notnecessarily require that both branches of the determining operation bepracticed. In other words, one of the branches of the determiningoperation can be deemed as an optional step.

FIG. 5 depicts a high level block diagram of a general purpose computeror system suitable for use in performing the functions described herein.For example, any one or more components or devices illustrated in FIG. 1or described in connection with the methods 300 and 400 may beimplemented as the system 500. As depicted in FIG. 5, the system 500comprises a hardware processor element 502 (e.g., a microprocessor, acentral processing unit (CPU) and the like), a memory 504, (e.g., randomaccess memory (RAM), read only memory (ROM) a disk drive, an opticaldrive, a magnetic drive, and/or a Universal Serial Bus (USB) drive), amodule 505 for determining a location of a wireless endpoint device in awireless network, and various input/output devices 506 (e.g., storagedevices, including but not limited to, a tape drive, a floppy drive, ahard disk drive or a compact disk drive, a receiver, a transmitter, aspeaker, a display, a speech synthesizer, an output port, and a userinput device (such as a keyboard, a keypad, a mouse, and the like)).

It should be noted that embodiments of the present disclosure can beimplemented in software and/or in a combination of software andhardware, e.g., using application specific integrated circuits (ASIC), ageneral purpose computer or any other hardware equivalents, e.g.,computer readable instructions pertaining to the methods discussed abovecan be used to configure a hardware processor to perform the steps,functions and/or operations of the above disclosed methods. In oneembodiment, the present module or process 505 for determining a locationof a wireless endpoint device in a wireless network can be implementedas computer-executable instructions (e.g., a software program comprisingcomputer-executable instructions) and loaded into memory 604 andexecuted by hardware processor 502 to implement the functions asdiscussed above in connection with the exemplary methods 300 and 400respectively. As such, the present module or process 505 for determininga location of a wireless endpoint device in a wireless network asdiscussed above in respective methods 300 and/or 400 (includingassociated data structures) can be stored on a non-transitory (e.g.,tangible or physical) computer readable storage medium, e.g., RAMmemory, magnetic or optical drive or diskette and the like.

It should be noted that the hardware processor can be configured orprogrammed to cause other devices to perform one or more operations asdiscussed above. In other words, the hardware processor may serve thefunction of a central controller directing other devices to perform theone or more operations as discussed above.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example only, and notlimitation. Thus, the breadth and scope of a preferred embodiment shouldnot be limited by any of the above-described exemplary embodiments, butshould be defined only in accordance with the following claims and theirequivalents.

What is claimed is:
 1. A method for determining a location of a wirelessendpoint device in a wireless network, the method comprising: receiving,via a processor of a network element of the wireless network, from eachof a plurality of base stations a plurality of signals and a pluralityof times of arrival, wherein each of the plurality of times of arrivalis associated with a particular signal of the plurality of signals,wherein each of the plurality of signals comprises a periodic sequencewith a constant envelope; and determining, via the processor, thelocation of the wireless endpoint device from the plurality of signalsand the plurality of times of arrival.
 2. The method of claim 1, whereinthe determining the location of the wireless endpoint device comprises:identifying a string of multipath components from the plurality ofsignals; determining which multipath component of the string ofmultipath components that are identified, is associated with an earliesttime of arrival of the plurality of times of arrival; and determiningthe location of the wireless endpoint device in accordance with themultipath component of the string of multipath components that isassociated with the earliest time of arrival of the plurality of timesof arrival.
 3. The method of claim 1, wherein each particular basestation of the plurality of base stations receives each of the pluralityof signals from the wireless endpoint device via a location channel,wherein the location channel is overlaid onto a signal of a long termevolution network.
 4. The method of claim 1, wherein each particularbase station of the plurality of base stations receives each of theplurality of signals from the wireless endpoint device via a locationchannel, wherein each of the plurality of signals is extracted by theparticular base station from the location channel.
 5. The method ofclaim 1, wherein each particular base station of the plurality of basestations receives the plurality of signals from the wireless endpointdevice via a plurality of paths.
 6. The method of claim 5, wherein theplurality of paths comprises at least one direct path between theparticular base station of the plurality of base stations and thewireless endpoint device.
 7. The method of claim 6, wherein the directpath comprises a shortest path between the particular base station ofthe plurality of base stations and the wireless endpoint device.
 8. Themethod of claim 5, wherein the plurality of paths comprises an indirectpath between the particular base station of the plurality of basestations and the wireless endpoint device, wherein the indirect pathcomprises a path traversed by a signal that is reflected on a structure.9. The method of claim 8, wherein the structure comprises a naturalterrain.
 10. The method of claim 8, wherein the structure comprises aman-made structure.
 11. A tangible computer-readable medium storing aplurality of instructions which, when executed by a processor of anetwork element of a wireless network, cause the processor to performoperations for determining a location of a wireless endpoint device inthe wireless network, the operations comprising: receiving from each ofa plurality of base stations a plurality of signals and a plurality oftimes of arrival, wherein each of the plurality of times of arrival isassociated with a particular signal of the plurality of signals, whereineach of the plurality of signals comprises a periodic sequence with aconstant envelope; and determining the location of the wireless endpointdevice from the plurality of signals and the plurality of times ofarrival.
 12. The tangible computer-readable medium of claim 11, whereinthe determining the location of the wireless endpoint device comprises:identifying a string of multipath components from the plurality ofsignals; determining which multipath component of the string ofmultipath components that are identified, is associated with an earliesttime of arrival of the plurality of times of arrival; and determiningthe location of the wireless endpoint device in accordance with themultipath component of the string of multipath components that isassociated with the earliest time of arrival of the plurality of timesof arrival.
 13. The tangible computer-readable medium of claim 11,wherein each particular base station of the plurality of base stationsreceives each of the plurality of signals from the wireless endpointdevice via a location channel, wherein the location channel is overlaidonto a signal of a long term evolution network.
 14. The tangiblecomputer-readable medium of claim 11, wherein each particular basestation of the plurality of base stations receives each of the pluralityof signals from the wireless endpoint device via a location channel,wherein each of the plurality of signals is extracted by the particularbase station from the location channel.
 15. The tangiblecomputer-readable medium of claim 11, wherein each particular basestation of the plurality of base stations receives the plurality ofsignals from the wireless endpoint device via a plurality of paths. 16.An apparatus of a wireless network for determining a location of awireless endpoint device in the wireless network, the apparatuscomprising: a processor; and a computer-readable medium storing aplurality of instructions which, when executed by the processor, causethe processor to perform operations, the operations comprising:receiving from each of a plurality of base stations a plurality ofsignals and a plurality of times of arrival, wherein each of theplurality of times of arrival is associated with a particular signal ofthe plurality of signals, wherein each of the plurality of signalscomprises a periodic sequence with a constant envelope; and determiningthe location of the wireless endpoint device from the plurality ofsignals and the plurality of times of arrival.
 17. The apparatus ofclaim 16, wherein the determining the location of the wireless endpointdevice comprises: identifying a string of multipath components from theplurality of signals; determining which multipath component of thestring of multipath components that are identified, is associated withan earliest time of arrival of the plurality of times of arrival; anddetermining the location of the wireless endpoint device in accordancewith the multipath component of the string of multipath components thatis associated with the earliest time of arrival of the plurality oftimes of arrival.
 18. The apparatus of claim 16, wherein each particularbase station of the plurality of base stations receives each of theplurality of signals from the wireless endpoint device via a locationchannel, wherein the location channel is overlaid onto a signal of along term evolution network.
 19. The apparatus of claim 16, wherein eachparticular base station of the plurality of base stations receives eachof the plurality of signals from the wireless endpoint device via alocation channel, wherein each of the plurality of signals is extractedby the particular base station from the location channel.
 20. Theapparatus of claim 16, wherein each particular base station of theplurality of base stations receives the plurality of signals from thewireless endpoint device via a plurality of paths.